A Kansas City teen will remain in protective custody in Chicago despite his mother's objections, after a judge found credible Wednesday a doctor's testimony that he suffered from medical child abuse.

Michelle Rider has been fighting to regain custody of her 16-year-old son, Isaiah, ever since he was placed into protective custody after she checked him into a Chicago hospital.

The teen was admitted to Ann & Robert H. Lurie Children's Hospital of Chicago after doctors in three other cities were unable to effectively treat his neurofibromatosis -- a painful condition that causes tumors to grow on his nerves.

But Lurie officials -- citing Michelle Rider's requests for stronger medications -- told a Cook County Court that it was best that Isaiah be taken into temporary protective custody, saying the boy's symptoms appeared to improve when his mother was not around.

The juvenile court judge ruled Wednesday that Isaiah must remain in protective custody for another 90 days, on the basis of a doctor's testimony of medical child abuse.

Juvenile court lawyers said the boy's health has gotten better in foster care where he wasn't being over-medicated.

Isaiah posted on Facebook that he wants to placed back with his mother, but the judge said he "can't just accept what his wishes are," and that "the main concern is returning the child to physical and emotional safety ASAP."

He will remain in protective custody for at least the next 90 days while the courts explore transfering the case to the state of Missouri, which would monitor Isaiah's case and report back to Illinois.

Michelle Rider, who cried in court while the determination was read, said before the hearing that she hoped it would all end soon.

"Return Isaiah to my care and return him home to Kansas City where he belongs. That's where he wants to be," Rider said. "Their allegations are ludicrous. That they would do anything like this is beyond me."

Michelle Rider has not been charged with any wrongdoing in the case.

Hospital officials have said they cannot comment on the case because of privacy concerns.

A tentative trial date to determine whether the case would be transferred to Missouri was set for Sept. 19.